Individual cylinder head for internal combustion engine



K. ZARUBA Oct. 15, 1968 INDIVLDUAL CYLINDER HEAD FOR INTERNAL COMBUSTION ENGINE Filed June 1, 1966 2 Sheets-Sheet 1 INVENTOR. 4222/ Zazzza K. ZARUBA Oct. 15, 1968 INDIVIDUAL CYLINDER HEAD FOR INTERNAL COMBUSTION ENGINE Filed June 1, 1966 2 Sheets-Sheet z United States Patent 3,405,696 INDIVIDUAL CYLINDER HEAD FOR INTERNAL COMBUSTION ENGINE Karl Zarnba, Detroit, Mich, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Filed June 1, 1966, Ser. No. 554,445 1 Claim. (Cl. 12341.82)

ABSTRACT OF THE DISCLOSURE A cylindrical cylinder head for a unifiow scavenged diesel engine is arranged to be received within a cylindrical opening of an engine cylinder block and includes four annularly spaced exhaust valves controlling an equal number of ports feeding a pair of exhaust passages which open through a peripheral wall of the cylinder head. A separately formed copper injector tube is centrally located between the exhaust ports to receive a fuel injector. A plurality of coolant openings, peripherally spaced on the lower wall, receive coolant and direct it inwardly to cool the lower wall, exhaust passages and injector tube. A coolant outlet opening is provided in the head upper wall.

This invention relates to cylinder heads for internal combustion engines and more particularly to a cylinder head of primarily cast construction adapted for closing the combustion chamber end of an individual cylinder in a uniflow scavenged two-cycle diesel engine.

In its more specific aspects, the invention contemplates a cylinder head of generally cylindrical configuration adapted to be received within a cylindrical opening of an engine cylinder block and provided with four annularly spaced exhaust valves controlling an equal number of ports which feed into a pair of exhaust passages opening through the peripheral wall of the cylinder head. A separate injector tube is located centrally of the cylinder head between the exhaust ports and extending through the upper and lower walls of the cylinder head. A plurality of strengthening bosses are annularly spaced on the inner surface of the peripheral wall extending between the upper and lower walls and have openings extending axially therethrough to receive bolts or other securing means for retaining the cylinder head in place in the engine cylinder block.

The walls of the cylinder head define a cavity through which coolant is circulated, a plurality of coolant inlet means being provided around the periphery of the lower cylinder head wall and spaced alternately between the securing means receiving openings to receive coolant from connecting passages in the engine cylinder block and discharge it radially inwardly along the inner surface of the lower wall. Such coolant inlet means may comprise pairs of intersecting drilled passages including axially directed passages extending upwardly from the lower wall and intersecting radially directed drilled passages opening to the cooling cavity adjacent the inner surface of the lower wall. The outer ends of the radial passages are plugged so that coolant is directed into the cavity across the inner surface of the lower wall and against the exhaust passage walls and injector tube. A coolant outlet opening is provided in the upper cylinder head wall to cooperate with an outlet connector for leading coolant out of the cylinder head.

These and other features cooperate to define a compact cylinder head construction utilizing a relatively small amount of metal for the size of cylinder it closes and permitting the economical use of high thermal strength cast iron to provide high resistance to thermal cracking. In addition, the cylindrical construction and small size as well as the specific cooling provisions result in more uniform 3,405,696 Patented Oct. 15, 1968 ice temperature distribution and reduce the amount of differential expansion of the cast walls, thereby reducing the metal stresses normally caused thereby and further increasing resistance to cracking of the cylinder head walls.

Due to its cylindrical construction, the exterior of the cylinder head is easily machined on an automatic lathe thus reducing manufacturing costs. Further, the coolant inlet openings are simply formed by drilling through the peripheral wall and the lower wall and plugging the outer portions of the passages through the peripheral wall.

These and other features and advantages of the invention will be more clearly understood by reference to the following description of a preferred embodiment having reference to the drawings in which FIGURE 1 is a partial cross-sectional view of an internal combustion engine having a cylinder head according to the invention;

FIGURE 2 is a view taken generally along the plane indicated by line 22 of FIGURE 1 and showing the cylinder head partially broken away to show portions of the interior construction;

FIGURE 3 is a partial cross-sectional view taken generally along the plane indicated by line 33 of FIG- URE 5;

FIGURE 4 is a cross-sectional view taken generally along the plane indicated by line 44 of FIGURE 2;

FIGURE 5 is a cross-sectional view taken generally along the plane indicated by line 55 of FIGURE 2;

FIGURE 6 is an exterior view of the cylinder head as seen in the direction of the arrows 6-6 of FIGURE 2; and

FIGURE 7 is a cross-sectional view taken generally along the plane indicated by line 77 of FIGURE 2.

Referring now to the drawings, there is shown an engine 10 comprising a cast cylinder block 12 having provision for a plurality of removable cylinder liners 14 in each of which a piston 16 is reciprocably disposed in a conventional manner. In the upper portion of the cylinder block a generally cylindrical opening 18 is provided above each cylinder liner to receive a cylinder head 20 which closes the upper end of the cylinder liner 14 and cooperates therewith and with the piston 16 to form a combustion chamber 22. A cover member 24 is secured to the upper portion of the cylinder block to form an enclosed compartment above the cylinder heads.

In the disclosed embodiment, inlet ports 26 are provided in the cylinder liner 14 which permit the periodic introduction of air charges into the combustion chambers. The removal of combustion products from the combustion chambers is accomplished through exhaust passages 28 in the cylinder head which are controlled by a plurality of cylinder head carried valves 30 and connect with outlet passages 32 in the cylinder block leading to external exhaust manifolds 34. A fuel injector 36 is located centrally of the head and extends into the combustion chamber 22 for the purpose of periodically delivering atomized fuel thereto. Actuation of the valves and fuel injector for each cylinder is accomplished by means of rocker arms 37 carried in the upper portion of the cylinder block. The valve actuating rocker arms engage valve bridges 38 which in turn engage the valves 30 and are guided by studs 39 carried in the cylinder head.

The cylinder head 20 which forms the present invention comprises a cast structure having a peripheral Wall 40 of generally cylindrical configuration formed integrally with upper and lower Walls 42 and 44 respectively, located parallel to and spaced from one another and coacting with the peripheral wall 40 to enclose a coolant retaining cavity A separately formed copper injector tube 48 extends through cavity 46 between the upper and lower walls centrally of the cylinder head to receive the fuel injector 36. The lower portion of the copper tube 48 is deformed at its end 50 adjacent the lower wall outer surface to retain the tube in sealing engagement with the lower wall while an O ring seal 52 is provided between the upper wall 42 and a flanged portion 54 of tube 48 to seal the upper end of the tube.

Four exhaust port openings 56 are located in lower wall 44 annularly disposed around the injector tube 48 and serve to communicate the exhaust passages 28 with the combustion chamber 22. Such communication is controlled by the exhaust valves 30, the ends of which engage valve seats 58 to close the port openings 56.

The exhaust passages 28 are formed by a pair of passage defining walls 60 which extend through the coolant cavity and are formed integrally with the lower wall 44 and the peripheral wall 40 opening therethrough at port openings 56 and exhaust openings 62 respectively. Passage defining walls 60 sweep around and are spaced from the injector tube 48 to permit the flow of coolant therebetween for cooling the passage walls 60 as well as the tube 48 and injector 36 carried therein.

Spaced around and formed integrally with the interior of peripheral wall 40 are a series of seven strengthening bosses 64, three of which are integrated with the outer ends of passage walls 60. Bosses 64 extend between the upper and lower walls 42 and 44 respectively and include axially directed bolt receiving openings 66 through which bolts 68 extend for retaining the cylinder head in position within the opening 18 provided in the cylinder block.

Alternately spaced between the openings 66 and around the lower periphery of the cylinder head are seven coolant inlet means 70. These inlet means are adapted to receive coolant from passages 72 in the cylinder block and direct it radially inwardly along the inner surface of the lower cylinder head Wall 44 and against the lower portions of the passage defining walls 60 adjacent valve seats 58, and the lower end of copper tube 48, surrounding the injector 36. Each of these coolant inlet means comprises a drilled passage 74 extending axially upwardly from the lower wall 44 adjacent its periphery and intersecting a second drilled passage 76 extending radially inwardly through the peripheral wall and opening to cavity 46 adjacent the inner surface of lower wall 44. A closure plug 78 closes the outer end of each passage 76 so that coolant flowing upwardly from cylinder block passages 72 moves upwardly through passage 74 and is directed inwardly along passage 76 being discharged radially inwardly along the inner surface of the lower cylinder head wall.

In order to provide for the discharge of coolant from the cylinder head coolant cavity 46 a discharge opening 80 is provided in the upper wall 42 of the cylinder head. A connecter 82 is mounted on the cylinder head upper wall to receive coolant passing through discharge opening 80 and carry it to other desired locations of the engine.

To permit the support and removal of casting cores forming the interior configuration of the coolant cavity a number of core support openings 84 are provided in the peripheral wall 40 and upper wall 42. These openings are closed by closure plugs 86 and serve no purpose in the completed cylinder head assembly.

While the foregoing description has been confined for purpose of illustration to a specific embodiment of the present invention, it is not intended that the invention be so limited but it is intended to cover all changes and modifications which do not constitute departures from the spirit and scope of the invention as defined by the following claim.

I claim:

1. A cylinder head for an internal combustion engine and comprising a peripheral wall of generally cylindrical configuration,

upper and lower spaced walls cast integrally with and intersecting said peripheral wall to define an enclosed coolant cavity,

fluid passage means through said cavity, said passage means being integrally cast with and opening through said peripheral wall and said lower wall and terminating at said lower wall in a plurality of openings forming valve controlled ports spaced around the center of said lower wall,

a plurality of coolant inlet passage means through said lower wall, each including a radially inwardly directed portion opening to the lower periphery of said cavity to direct incoming Coolant along the inner surfaces of said lower wall and against said fluid passage means and a separately formed tubular component receiving member extending between and opening through said upper and lower walls and located centrally thereof, said member being spaced from said fluid passage means to permit coolant flow therebetween,

said coolant inlet passage means including a plurality of radially inwardly directed drilled passages spaced around and extending through said peripheral wall, said drilled passages extending generally parallel to and opening inwardly adjacent said lower wall,

a plug closing the outer end of each said drilled passage and a plurality of drilled passages through said lower wall adjacent its periphery, one intersecting each of said first drilled passages inwardly of said plug.

References Cited UNITED STATES PATENTS 1,107,946 8/1914 Hesselman l23--4l.82 1,526,744 2/1925 Eberle 12341.82 X 2,619,078 11/ 1952 Witzky et al.

2,739,579 3/1956 Ware et al l23-41.82 3,081,755 3/1963 Kotlin et al. 1234l.77 3,315,652 4/1967 Rios et al. 12341.31 3,334,617 8/1967 Palkowsky l2332 AL LAWRENCE SMITH, Primary Examiner. 

